1. Technical Field
The invention relates to the general field of additives to improve the performance of lubricating oils and function as an engine treatment oil additive and/or complete motor oil lubricant. A preferred embodiment of the present invention comprises effective amounts of a combination of chemical constituents including an oil soluble molybdenum additive, base oil (synthetic, mineral, and/or Group III semi-synthetics), a dispersant inhibitor containing zinc dithiophosphate, and viscosity index improvers. Addition of selected synthetics such as polyalphaolefin and/or esters such as a diester or polyolester, and/or a nonaqueous polytetrafluoroethylene compound, and/or a antiwear/extreme pressure agent such as a metal containing borate compound such as a borate ester, may be used to formulate one or more embodiments of the additive in combination with a conventional crankcase lubricant containing mineral oil, synthetic oil, semi-synthetic, or combinations thereof up to 50 volume percent and more preferably from about 10 to 40 volume percent, more preferably from about 15 to 30 percent and most preferably from about 20 to about a 25% volume/percent after dilution with motor oil, wherein typically 1 quart is blended with 4 or 5 quarts of motor oil. The various constituents are preblended and/or sold as a complete motor oil formulation.
2. Description of the Prior Art
Lubrication involves the process of friction reduction, accomplished by maintaining a film of a lubricant between surfaces which are moving with respect to each other. The lubricant prevents contact of the moving surfaces, thus greatly lowering the coefficient of friction. In addition to this function, the lubricant also can be called upon to perform heat removal, containment of contaminants, and other important functions. Additives have been developed to establish or enhance various properties of lubricants. Various additives which are used include viscosity improvers, detergents, dispersants, antioxidants, extreme pressure additives, and corrosion inhibitors.
Anti-wear agents, many of which function by a process of interactions with the surfaces, provide a chemical film which prevents metal-to-metal contact under high load conditions. Wear inhibitors which are useful under extremely high load conditions are frequently called xe2x80x9cextreme pressure agentsxe2x80x9d. Certain of these materials, however, must be used judiciously in certain applications due to their property of accelerating corrosion of metal parts, such as bearings. The instant invention utilizes the synergy between several chemical constituents to provide an additive formula which enhance the performance of conventional engine oil and inhibits the undesirable side effects which may be attributable to use of one of more of the chemical constituents when used at particular concentrations.
Several references teach the use of individual chemical components to enhance the performance of conventional engine oil. For instance, U.S. Pat. No. 4,879,045 by Eggerichs adds lithium soap to a synthetic base oil comprising diester oil and polyalphaolefins which can comprise an aliphatic diester of a carboxylic acid such as di-2-ethylhexylazelate, di-isodecyladipate, or ditridecyladipate, as set forth in the Encyclopedia of Chemical Technology, 34th addition, volume 14, pp 477-526, which describes lubricant additives including detergent-dispersant, viscosity index (VI) improvers, foam inhibitors, and the like.
U.S. Pat. No. 4,333,840 to Reick teaches a hybrid PFTE lubricant and describes an optional addition of a molybdenum compound in a carrier oil. It uses a carrier oil diluted by a synthetic lubricant of low viscosity in order to provide a viscosity that is xe2x80x9cacceptable in weapons applicationsxe2x80x9d. The formulations are suggested for lubricating skis or weapons; however, there is no suggestion that they are applicable to lubrication of internal combustion engines in combination with the constituents of the present claimed invention. U.S. Pat. No. 4,349,444 by Reich teaches the use of fluorochemical surface active agents or surfactants to stabilize an aqueous dispersion of colloidal PTFE particles, which Applicant believes would tend to be corrosive and undesirable in an engine lubricating oil.
Furthermore, U.S. Pat. Nos. 4,615,917 and 4,608,282 by Runge teach blending sintered fluoropolymer (e.g., PTFE) with solvents which evaporate to leave a thin film when the formulation is sprayed or applied as a grease to a metal surface, e.g., boat hulls, aircraft, dissimilar metals.
The present invention comprises various formulations of lubricant additive concentrates for addition to conventional engine oil or as motor oil lubricants incorporating said additives therein as complete formulas for improving the lubricating properties of the engine oil, enhance the performance of the engine, and reduce engine wear and possibly reduce the consumption of the oil.
One preferred embodiment of the engine treatment oil additive comprises a blend of chemical constituents including an oil soluble molybdenum additive, a dispersant inhibitor containing zinc dithiophosphate, and a viscosity index improvers in a synthetic base stock such as a polyalphaolefin. A selected synthetic constituent comprising a ester such as a diester, and/or a polyolester, provides optimal performance characteristics to the composition. The composition may include a mineral oil or a Group III hydrogenated oil as an additive to the base formula. A nonaqueous polytetrafluoroethylene compound may be added to further improve the lubricity of the composition. A metal containing a high pressure antiwear agent such as a borate compound and preferably a borate ester may be added optionally as a corrosion inhibitor for yellow metals. The constituents may be combined to give particularly performance properties for formulating various embodiments of the lubricant additive concentrate for use with conventional crankcase engine oil or the formulation of a complete engine oil incorporating the additive concentrate package.
The additive is used in combination with a conventional crankcase lubricant containing mineral oil, synthetic oil or combinations thereof up to about 50 percent by volume, more preferably from about 10 to 40 percent by volume, more preferably from 15 to 30 percent by volume, and most preferably from about 20 to about a 25% volume/percent.
Another preferred embodiment of the engine treatment oil additive comprises a blend of chemical constituents including an oil soluble molybdenum additive, a synthetic, mineral, or Group III semi-synthetic base oil. Moreover, a dispersant inhibitor containing zinc dithiophosphate, polytetrafluoroethylene, and viscosity index improvers are blended together and added thereto. An extreme pressure antiwear agent such as a borate compound may also be utilized in the present composition.
The improved performance of the engine additive in comparison with conventional crankcase lubricants is attributable to optimizing the design parameters for each of the individual chemical constituents and combining the chemical constituents to obtain surprisingly good results including improved: wear, oxidation resistance, viscosity stability, engine cleanliness, fuel economy, cold starting, reduced oil consumption, and inhibition of acid formation. The novel engine additive formulation comprises a combination of compounds, ingredients, or components, each of which alone is insufficient to give the desired properties, but when used in concert give outstanding lubricating properties. Additional components may be added to the engine additive formulation to enhance specific properties for special applications. Moreover, the formulation is compatible with engine warranty requirements, i.e., service classification API SH and SJ.
The lubricating and oil-based functional fluid compositions of the present invention are based on natural and synthetic lubricating oils and mixtures thereof in combination with the additives.
The individual components can be separately blended into the base fluid or can be blended therein in various subcombinations. Moreover, the components can be blended in the form of separate solutions in a diluent. Blending the components used in the form of an oil additive concentrate simplifies the blending operations, reduces the likelihood of blending errors, and takes advantage of the compatibility and solubility characteristics afforded by the overall concentrate. Of course, the preblended complete motor oil is convenient to use and is often preferable for adding to an engine one quart or less at a time such as for routine maintenance of older cars having engine wear and requiring additional motor oil lubricant between oil changes. The complete motor oil does not require the consumer to determine the amount of additive required for optional performance when blending with a conventional motor oil in small quantifies between oil changes.
The combination of chemical constituents of the present invention are not disclosed by any known prior art references. The incorporation of molybdenum compounds, extreme antiwear compounds such as boric acid agents and/or a PFTE lubricant provide improved performance to motor oil and greases. Moreover, the incorporation of semi-synthetic oils defined by the American Petroleum Institute (API) as severely hydro cracked oils) provide an means to reduce the cost of lubricating oils while maintaining many of the desirable characteristics of synthetic oil.
These lubricating compositions are effective in a variety of applications including crankcase lubricating oils for spark-ignited and compression-ignited internal combustion engines, two-cycle engines, aviation piston engines, marine and low-load diesel engines, and the like. The invention will find use in a wide variety of lubricants, including motor oils, greases, sucker-rod lubricants, cutting fluids, and even spray-tube lubricants. The invention has the multiple advantages of saving energy, reducing engine or other hardware maintenance and wear, and therefore, provides an economical solution to many lubricating problems commonly encountered in industry or consumer markets. It is also contemplated that the formulation may be applicable to automatic transmission fluids, transaxle lubricants, gear lubricants, hydraulic fluids, and other lubricating oil compositions which can benefit from the incorporation of the compositions of the instant invention.
More particularly, one preferred concentrate for addition to conventional motor oil for improving the lubricating properties of the motor oil and enhancing the performance of the engine comprises the following chemical constituents: an oil soluble molybdenum additive, a (xe2x80x9csynthetic basexe2x80x9d) such as polyalphaolefin (PAO), a synthetic polyolester, and/or a synthetic diester, a Dispersant Inhibitor (DI) package containing zinc dithiophosphate (ZDP) and which may also contain a detergent and/or corrosion inhibitor, such as CHEMALOY D-036; a Mineral Oil Base Stock; and a Viscosity Index Improver, such as for example, (SHELLVIS 90-SBR); and an extreme anti-wear agent (borate ester). The addition of a nonaqueous polytetrafluoroethylene, (xe2x80x9cPTFExe2x80x9d) provides additional protection and increased performance characteristics.
Finally, a preferred composition of the instant invention provides improved lubricating properties and comprises a lubricant concentrate for dilution with conventional, synthetic blend, and/or fully synthetic motor oil comprising in combination: an effective amount of an oil soluble molybdenum additive; an effective amount of a base oil selected from the group consisting of a synthetic base oil, a mineral oil, a severely hydro cracked oil, alone and in combination one with another; and an effective amount of less than 1000 ppm of an elemental boron. Moreover, a lubricating composition comprising a major amount of an oil of lubricating viscosity and a minor amount of the concentrate aforementioned concentrate additive provides a complete motor oil with improved lubricating properties.